Radiation and Human Beings

Radiation and Human Beings

A study commissioned by Tehelka newspaper found that four-fifths of
the Capital’s area is exposed to “unsafe” radiation levels. While this
is genuine cause for concern, such radiation only constitutes the tip of
the proverbial iceberg. Far more dangerous radiation sources surround
us night and day: bricks, and other building materials.

Radiation and cell phone radiation: the picture

There are two types or radiation: (1)
ionizing which knocks electrons from atoms producing ions, ex. x-rays, and
(2) nonionizing, which usually does not dislodge the electron and is considered not as hazardous as ionizing radiation,
for it only heats the surface layers of its target. The radiation from
mobile phones and cell towers is believed to be of the second, less
harmful kind.

Tests on animals showed no harmful effects of radiation from
cell phones. WHO in 2005 based upon the consensus view of the scientific
and medical communities, stated that cancer is unlikely to be caused by
cellular phones or their base stations and that reviews have found no
convincing evidence for other health effects. European Commission in
2009 echoed that exposure to radio frequency fields is unlikely to lead
to an increase in cancer in humans. Studies in other countries like
Britain, Germany, Swedan shows similar findings.

There is however another problem. The heat created by impinging
radiation can indeed damage cells by overheating them. Since radio waves
from a mobile telephone handset are absorbed by the part of the body
adjacent to the phone, this causes heating of the tissue. While normal
blood flow easily takes care of small amounts of heat, there is concern
that prolonged use could cause headaches, fatigue, tissue swelling,
tingling and, potentially, long-term damages.

The bigger worry: ionizing radiation

A greater worry is the ionizing radiation which is constantly present
in the environment and is emitted from a variety of natural and
artificial sources. This is called background radiation and one of its
primary contributions is from the atmosphere, in form of radon gas
which is released from the Earth's crust and subsequently decays into
radioactive atoms that become attached to airborne dust and
particulates. Other radioactive materials such as thorium are present in
significant amounts in many sorts of rocks, other building materials
and in the soil.

Listed below are a few of common building materials and their
estimated levels of uranium, thorium and potassium.

Material

Uranium

Thorium

Potassium

ppm

mBq/g (pCi/g)

ppm

mBq/g (pCi/g)

ppm

mBq/g (pCi/g)

Granite

4.7

63 (1.7)

2

8 (0.22)

4.0

1184 (32)

Sandstone

0.45

6 (0.2)

1.7

7 (0.19)

1.4

414 (11.2)

Cement

3.4

46 (1.2)

5.1

21 (0.57)

0.8

237 (6.4)

Limestone concrete

2.3

31 (0.8)

2.1

8.5 (0.23)

0.3

89 (2.4)

Sandstone concrete

0.8

11 (0.3)

2.1

8.5 (0.23)

1.3

385 (10.4)

Dry wallboard

1.0

14 (0.4)

3

12 (0.32)

0.3

89 (2.4)

By-product gypsum

13.7

186 (5.0)

16.1

66 (1.78)

0.02

5.9 (0.2)

Natural gypsum

1.1

15 (0.4)

1.8

7.4 (0.2)

0.5

148 (4)

Wood

-

-

-

-

11.3

3330 (90)

Clay Brick

8.2

111 (3)

10.8

44 (1.2)

2.3

666 (18)

ppm- Part Per Million; mBq/g- Megabecquerel Per Gram (One Bq is the
activity of a quantity of radioactive material in which one nucleus
decays per second); pCi/g- Picocuries Per Gram (Picocurie is the amount
of radioactivity in a particular solid substance.)Other sources of ionizing radiation

Other natural and man-made sources of this ionizing radiation are

Radioactive material in earth. These include sources in food and
water, which are incorporated in the body, and in building materials and
other products that incorporate those radioactive sources

From space, in form of cosmic rays: flight crew are at particular
risk, because of the reduced filtering by our atmosphere at cruising
altitudes.

From the radioactive atoms produced in the bombardment of atoms in
the upper atmosphere by high-energy cosmic rays.

Naturally occurring sources are responsible for the vast majority of
radiation exposure. About 3% of background radiation comes from man-made
sources such as:

Nuclear power station or nuclear fuel reprocessing accidents (though
these are rare)

Normal operation of facilities used for nuclear power and scientific
research

Emissions from burning fossil fuels, such as coal fired power plants

Emissions from nuclear medicine facilities and patients

Damage ionizing radiation can cause

The body has repair mechanisms against damage induced by radiation as
well as by chemical carcinogens. Consequently, biological effects of
radiation on living cells may result in three outcomes: (1) injured or
damaged cells repair themselves, resulting in no residual damage; (2)
cells die, much like millions of body cells do every day, being replaced
through normal biological processes; or (3) cells incorrectly repair
themselves resulting in a biophysical change.

The degree of damage caused by radiation depends on many factors -
dose, dose rate, type of radiation, the part of the body exposed, age
and health. Some of the symptoms of radiation sickness -- the result of
extreme exposure, as for instance faced by atom bomb victims -- include
actual burns to the skin, nausea, vomiting, and diarrhea, and can cause
death.

Radiation and Cancer

The correlations between radiation exposure and the development of
cancer are mostly based on populations exposed to relatively high levels
of ionizing radiation (e.g., Japanese atomic bomb survivors, and
recipients of selected diagnostic or therapeutic medical procedures).
Cancers associated with high dose exposure (greater than 50,000 mrem)
include leukemia, breast, bladder, colon, liver, lung, esophagus,
ovarian, multiple myeloma, and stomach cancers.

The US Department of Health and Human Services literature also suggests a
possible association between ionizing radiation exposure and prostate,
nasal cavity/sinuses, pharyngeal and laryngeal, and pancreatic cancer.

Although radiation may cause cancers at high doses and high dose
rates, currently there are no data to unequivocally establish the
occurrence of cancer following exposure to low doses and dose rates --
below about 10,000 mrem (100 mSv). Those people living in areas having
high levels of background radiation -- above 1,000 mrem (10 mSv) per
year-- such as Denver, Colorado have shown no adverse biological
effects.

How to reduce ionizing radiation?

Do not sleep with your head near a wall.

Ventilate well, particularly basements

Be selective in use of construction materials

How to avoid cell phone radiation?

Use hands-free to decrease the EMR radiation to the head, and ensure
that a ferrite bead is clipped to the headset to absorb radiation.

Keep the mobile phone away from the body, and use a speaker phone.

Do not use telephone in a car without an external antenna.

Use a landline for longer telephone calls.

Avoid using your cell phone in metallic enclosures such as
elevators, where radiation has nowhere to go but into your body.

Use a cell phone radiation shield. Many companies offer such
shields.

Look for the SAR number of the mobile phone before buying it. SAR,
Specific Absorption Rate is the measurement rate at which radiation
absorbed by the human body is measured. Lower number indicates a lower
radiation exposure risk. Every cell phone model sold in the US has SAR information in
its manual.